CD8A and colorectal cancer: TILs have long been thought to be prognostic in solid organ malignancies.[48] This has particularly been recognised in colorectal cancer, with a movement to develop a validated instrument, the immunoscore, to be added to standard prognostic markers.[49] Whilst some researchers have reported improved survival with CD8+ TIL infiltrates, [7, 8, 15] others have not.[23, 24] The most consistent data to date has been published by Donnem et al[8] which suggests a simple scoring scale for stromal CD8+ count can be highly prognostic.